We have studied excitonic contributions and Bloch oscillation in the conduction miniband (continuum contributions) to the terahertz (THz) emission from semiconductor superlattices. THz emission frequency of the continuum contribution agrees with the Bloch frequency, while that of the excitonic contribution exhibits a nonlinear dependence on the applied bias field. We have found that the excitation spectrum of the continuum contribution shows a characteristic lineshape associated not only with the three‐dimensional nature of the band‐to‐band transition but also with coupling between spatially direct excitons and indirect continuum states.